Many online and standalone applications provide maps to users. For example, some web sites (such Google, MapQuest, and the BING service) allow users to request maps, and also use maps to provide directions. An automobile navigation box or dashboard navigation console uses maps to provide real-time interactive directions. The geographic information that is used to display maps is generally built from a visual analysis of geographic features of the land. For example, a map provider such as Navteq or Tele Atlas may perform computer-assisted analysis of aerial or satellite photographs to identify the true locations of roads. However, such maps may omit certain roads, or other topographic features (e.g., trails, bodies of water, etc.). In some cases, a road or other feature is omitted from a map because it was not discernible from the photographs that were used to generate the map. In other cases, a road or feature is omitted because it is new—e.g., a new neighborhood or a new ski trail might be built after the map is created. In this case, it may be possible for a person to add the feature to the map by hand.
Editing a map by hand, however, can be tedious. For example, in order to add a road to a map, a user would have to trace the location of the road by hand over an existing map or over an existing aerial or satellite photograph. Similarly, to add a body of water such as a lake, a user would have to trace the outline of the body of water by hand.